Ignore unknown test app messages (#2103)

This updates the test app to ignore unknown window events. Some
extensions, like metamask, send seemingly arbitrary messages to the
window which confuses the test app.

With these changes we try to figure out if a message was intended for us
by

1. Ensuring a request was started
2. Checking the jsonrpc response ID

demos/test-app/src/index.tsx

@@ -415,6 +415,16 @@ function handleFlowReady(evnt: MessageEvent) {
 }
 
 function handleFlowFinished(evnt: MessageEvent) {
+  if (latestOpts === undefined) {
+    // no inflight requests, so we don't expect a response.
+    return;
+  }
+
+  if (evnt.data?.id.toString() !== latestOpts.flowId.toString()) {
+    // If this is not a response to a flow we started, ignore it
+    return;
+  }
+
   try {
     // Make the presentation presentable
     const verifiablePresentation = evnt.data?.result?.verifiablePresentation;